Carburetor



July '26, 1932.

F. H. HEITGERV CARBURETOR Filed Mairch 5, 1928 Patented July 26, 1932 UNITED STATES FRANK H. HEITGEBQOI FLINT, MICHIGAN cannunn'ron Application filed March 3, 1928. Serial No. 258,740.

This invention relates to certain new and useful improvements in carburetors and more particularly to carburetors for internal combustion engines used in connection with motor vehicles and the like where the speed is variable, varying from a minimum speed to a high speed and where it is required to feed fuel to a carburetor posterior of the throttle in the carbureting passage for the minimum or idling speed and to augment the fuel feed .as the throttle is opened and before the main feed comes into action fully and is a companion application of my application filed on even date herewith.

The main object of this invention is to pro; vide an idling and transfer passage having sufiicient area to allow the fuel mixture to ass above a projection on the throttle when the throttle valve is in closed position for idlingso that a portion only of the outlet of the idling and transfer passage is in constant communication with the carbureting passage to the engine side thereof and opens an addi tional portion of said outlet as throttle opens for transfer. 1

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined by the appended claim.

In the drawing,

Figure 1 is a side elevation through a carburetorconstructed in accordance with my invention partly in elevation;

Figure 2 is a detail section showing the outlet to the idling passage circular;

Figure 3 is a detail vertical section show- 7 ing the throttle inclosed position with the upper portion of the idling passage in constant communication with the carbureting passage to the engine side of the throttle and Figure 4is a detail section showing the outlet to the idling passage rectangular in shape with a projection'of the throttle partly closing the same.

In the embodiment'of my invention as shown, I have illustrated what is known in the trade as a plain tubetype of carburetor comprising a body A having a-carbureting passage B terminating at its u per end in an outlet B and at its lower en in a lateral air inlet B provided with a choker valve B for controlling the admission of air thereto in the usual manner.

Arranged in the carbureting passage is a Venturi tube 1 into which extends a main fuel nozzle 2 which is in communication with a main fuel passage 3 extending from a float bowl 4 which is of the ordinary construction now in general use on carburetors, the flow of fuel from the bowl being controlled by a removable plug 5 having a calibrated orifice for allowing the maximum amount of fuel to pass therethrough.

' An auxiliary fuel passage 6 is formed in one wall of the carbureting passage and in the embodiment of my invention as shown, issupplied with fuel from an auxiliary reservoir 7 extending from the main fuel passage 3. The lower end of the auxiliary fuel passage 6 is enlarged'to receive the upper end of the reservoir which is provided with a restricted outlet 8 subjected to suction and is adapted to feed fuel to the auxiliary passage 6 at substantially closed throttle position and to feed air to the main fuel passage 3 as the throttle is moved into open position substantially as described in the patent issued to Guthrie, December 5, 1916, No. 1,207,029. While I have shown the auxiliary fuel passage 6 supplied with fuel from an auxiliary reservoir, I do not wish to limit myself to any particular means of supplying fuel thereto, as I am aware that the same can be supplied with fuel from any source of supply, such as a 'well or directly from the fuel bowl without departing from the spirit of my invention which will be hereinafter fully described.

The fuel passage 6 for idling and transfer f'uel terminates at its upper end in a circular opening 7 of such a size that the projection or lip 8' of the throttle valve 9 only partially closes the same so that the upper portion of the opening is in constant communication with the carbureting passage to the engine side of the throttle valve and as the throttle moves into open position, more of this portfeeds fuel than at idling opening of the throttle valve, as throttle is further opened the lower portion of hole will be opened by throttle, suction will dominate on the upper part of the hole and cause air or a weak mixture to be fed from below the throttle valve into the lower portion of the opening and be discharged with the rich mixture from the upper portion, thereby diluting the latter, the throttle valve splitting the opening so that substantially the same result is obtained as fully described in my companion application.

In the construction of carburetor as herein shown with the throttle valve arranged at an angle, when the throttle is opened, the lip carried thereby while moving towards the carburetor passage outlet also moves away from the wall of said passage and enlarges the fuel feeding space from what it originally was so as to effect the added feed for transfer.

An air port 10 is formed in the fuel passage 6 controlled by a screw 11 of the ordinary construction now in general use on carburetors for controlling the communication between the fuel passage and the atmosphere to adjust the air for proper mixture.

The throttle valve 9 is carried by a shaft 12 extending transversely through the carbureting shaft and carries an operating arm constructed in substantially the same manner as disclosed in my companion application for preventing the same from being strained or distorted when moved into closed position.

A suitable opening 13 is formed in a throttle valve for providing the proper amount of air for idling and of course, where the idling speed requirements are not exact in large production, instead of using a throttle valve with an opening for supplying the air from the anterior to the posterior side of the throttle, the wall of the carbureting passage could be provided with an opening as shown in my companion application for by-passing the air around the edge of the throttle. K

In the modification shown in Figure 4, the fuel passage 6 terminates in a rectangular opening 14, the upper portion of which is in constant communication with the carbureting passage to the engine side of the throttle and the lip 15 of the throttle valve 16 closes a. portion of the same so that I am able to obtain the same result obtained with a circular opening.

While in the drawing I have shown a carburetor having an auxiliary well for supplying fuel to the idling passage, I am aware that fuel can be supplied to this passage from any suitable source of supply Without departing from the spirit of my invention but when fuel is supplied from an auxiliary well as shown, the operation of the carburetor will be substantially the same as that disclosed in my companion application.

In the specification I have used the term transfer to mean the interval or degree of throttle opening,'where a single fixed idling feed of proper mixture would be too lean to carry the motor before the main jet started to feed and as throttle is slightly opened; otherwise during this time the mixture would be too lean from the idle feed alone.

From the foregoing description it will be seen that I have provided a carburetor with a novel form of idling means in which the transfer stages from idling to open throttle position to where main feed starts are accomplished substantially in the same manner as accomplished in my companion application with a single opening instead of two openings.

What I claim is:

The combination with a carburetor, of a carbureting passage provided with an air inlet and means for connecting the upper end to the induction pipe of an internal combustion engine, a main fuel feed discharging into said carbureting passage, an auxiliary fuel passage, a throttle mounted in said carbureting passage having a member for closing thelower portion of the outlet of the auxiliary passage when the throttle valve is in an inclined position in substantially closed position, said throttle valve being mounted to move into open position on the side controlling said auxiliary passage in the direction of travel of fuel and air passing through said carbureting passage, said throttle valve having an opening in the side opposite to said member at sub stantially the lowest part when in angular position for feeding air posterior of said throttle valve to the fuel collected thereon when the throttle valve is closed or substantially closed.

In testimony whereof I hereunto afiix my signature.

FRANK H. HEI'IGER. 

